Galvanic cells of lithium-metal batteries, which usually include an anode made of metallic lithium or a lithium alloy, as well as of lithium-ion batteries, which usually include an anode made of an intercalation material, such as graphite, usually have a cell housing, in whose inner chamber the electrochemically active components of the cell, such as the anode, the cathode and the electrolyte are situated.
In numerous applications, battery cells are situated in greater numbers in direct proximity to cooling arrangement and/or tempering arrangement. There are batteries, for example, in which the battery cells are situated in a battery housing in such a way that they are partially or completely surrounded by cooling arrangement or tempering arrangement, which is usually a liquid.
During the service life of a battery, it is possible, however, that leakage is created in a cell housing, for instance, by aging effects, such as corrosion, external force effects or other causes. The leakage is possible at a plurality of places of the cell housing, among others at seals, welding seams, corners or edges of the cell housing or also at other places of the cell housing. When a leakage occurs, cell components, such as electrolytic liquid, may exit from the cell housing, or rather materials from the environment of the cell housing, such as cooling and/or tempering arrangement or air may penetrate into the cell housing, which is able to lead to vehement reactions, in which the battery may be damaged irreversibly.
In addition, the galvanic cells, particularly of lithium-metal batteries and lithium-ion batteries may have a safety device which opens the cell housing when the inside pressure in the cell housing rises above a critical value, to prevent the bursting of the cell housing. In their functioning, these safety devices resemble a rupture disk, and open the cell housing irreversibly, which is why in this case, too, cell component may exit from the cell housing or materials from the surroundings of the cell housing may penetrate into the cell housing, and the battery may be damaged irreversibly.
European document EP 0 951 080 B1 discusses a three-layered battery separator which has a shut-down layer which melts at about 115° C.